Acute lower respiratory tract infections are a leading cause of morbidity and mortality world-wide. Streptococcus pneumoniae (pneumococcus) is the most common bacterial cause of community-acquired pneumonia. Recovery from pneumococcal pneumonia results in the formation of resident memory CD4+ T cells, which act on lung epithelial cells to accelerate immune responses. Alveolar macrophages (AMs) are tissue-resident macrophages localized in the air spaces, where they orchestrate the lung anti-microbial responses. We hypothesized that recovery from pneumococcal pneumonia results in remodeling of the pool of alveolar macrophages, which act in concordance with other immune cells to protect the lungs from future infections. Although AM numbers were unchanged in experienced lungs, their surface phenotype showed significant changes, most prominently an increased MHC-II and a decreased SiglecF. This experienced AM phenotype was regionally-localized and long-lasting. Experienced AMs also exhibited extensive remodeling on the metabolomics and transcriptional level. Experienced AMs demonstrated significant increases in phosphocreatine and its metabolite precursors. The transcriptional analyses also revealed extensive changes. At baseline, experienced AMs exhibited a significant reduction in cell cycle activity and mRNA processing compared to naïve mice. During acute pneumonia, experienced AMs exhibited significant increases in immune signaling and energy metabolism. Moreover, transcriptional data also revealed strong but imperfect enrichment of a signature previously associated with IFN𝛾 signaling and marrow-derived AMs. IFN𝛾 gain and loss of functions experiments corroborated transcriptional data and revealed an essential role for IFN𝛾 in directly driving the AM MHC-II remodeling. Several immune cells produced IFN𝛾, with neutrophils being the most prominent source after the 1st pneumococcal challenge but other cells predominating after the 2nd pneumococcal challenge. CD4+ T cell depletion studies demonstrated that AMs' experienced phenotype was independent of CD4+ T cells. In contrast to naïve mice, lineage-tracing studies demonstrated that marrow-derived AMs predominately constitute the experienced AM pool. Upon experience, both embryonic AMs and marrow-derived AMs demonstrated similar remodeling for both SiglecF and MHC-II on their surfaces. While all AM similarly remodeled independent of their origin, marrow-derived AMs in experienced lungs displayed some differences from their embryonic counterparts, being less phagocytic. In conclusion, recovery from pneumococcal pneumonia remodels the pool of alveolar macrophages to acquire adaptive characteristics. This remodeling involves a combination of recruitment of new cells and trained immunity via IFN𝛾 signaling.

Streptococcus pneumoniae is typically an asymptomatic colonizer of the upper respiratory tract but can cause invasive disease in susceptible populations. Pneumococcal vaccines which are currently in use have failed to significantly reduce colonization by S. pneumoniae. To control invasive pneumococcal disease, novel strategies must be utilized. One such strategy is to reduce or eradicate colonization by pneumococcus. Supplementary vaccination with pneumococcal proteins important for colonization could serve to prime the immune system against these targets. This study serves as an initial step towards identification of crucial pneumococcal colonization proteins which may previously have been uncharacterized. Assessing the immune reactivity of human serum to isolated pneumococcal membrane proteins allowed for selection of proteins for analysis via mass spectrometry. Results of MS produced several potential protein targets for further research. Identification of these key surface proteins will pave the way for the creation of a more robust supplementary vaccine, and an improved understanding of the role of non-immunogenic pneumococcal surface proteins.

No description available.

Streptococcus pneumoniae (pneumococo) é um importante patógeno humano, responsável por graves infecções das vias respiratórias. O principal fator de virulência desse microrganismo é a cápsula polissacarídica (PS), antígeno das vacinas atuais, que são elaboradas com os PS purificados de cepas de pneumococo prevalentes na população. O objetivo desse trabalho foi desenvolver um processo de purificação do PS do sorotipo 14, responsável por 39% das doenças em crianças de 0-6 anos no Brasil. A metodologia de purificação envolveu separação celular por microfiltração tangencial e concentração do microfiltrado com membrana de ultrafiltração tangencial de 50 kDa. O produto dessa etapa foi diafiltrado com dodecil sulfato de sódio em membrana de ultrafiltração tangencial de 30 kDa, seguido de precipitação com ácido tricloroacético a 5%, precipitação por etanol (20% e 60%) e cromatografia de troca aniônica. A pureza do PS foi avaliada pelo conteúdo de proteínas e ácidos nucleicos remanescentes e o tamanho por cromatografia de exclusão molecular. O PS foi obtido com pureza e tamanho requeridos pelos órgãos regulatórios e o rendimento final do processo foi de 65%. / Streptococcus pneumoniae (pneumococcus) is an important human pathogen responsible for severe respiratory tract infections. The main virulence factor of this microorganism is the capsular polysaccharide (PS), which is the antigen of all current vaccines, which are prepared with purified PS of pneumococcal strains prevalent in the population. The objective of this work was to develop a new purification process for PS of serotype 14, responsible for 39% of diseases in children of 0-6 years old in Brazil. The purification method involved cell separation by tangential microfiltration and concentration of cell-free culture broth containing PS by tangential ultrafiltration (50 kDa). The product of this step was diafiltrated with sodium dodecyl sulfate by tangential ultrafiltration (30 kDa), following by 5% trichloroacetic acid precipitation, 20% and 60% ethanol precipitation and anion exchange chromatography. The PS purity was evaluated by the content of residual proteins and nucleic acids, and the molecular mass by size exclusion chromatography. The purity and molecular mass requirements were achieved and the process global yield was 65%.

Acute lower respiratory tract infections are a persistent and pervasive public health burden, often caused by Streptococcus pneumoniae. Hospitalization rates due to pneumonia fall dramatically during early childhood, remain low during early adult years, and then increase steadily around middle age. The low-susceptibility period of early adulthood is likely due to frequent respiratory exposures to diverse pneumococcal serotypes resulting in serotype-independent heterotypic immunity. We hypothesize that resolution of repeated respiratory pneumococcal infections establish capsule-independent, lung-resident adaptive immunity that protects against subsequent unrelated pneumococcal pneumonia. In our model of naturally acquired heterotypic immunity, mice are infected with diverse serotypes of pneumococci in the respiratory tract, given time to recover, and then challenged by pulmonary infection with a highly virulent serotype 3 pneumococcus (Sp3). Prior exposures to unrelated pneumococci resulted in multi-log reductions in Sp3 bacterial lung burdens and long-term sterilizing immunity. The enhanced lung defense during pneumonia included more Th17 cells in the lung and significantly elevated IL-17A as well as neutrophils in the airspaces. Depletion of CD4+ cells resulted in less effective antibacterial defense. Upon ex vivo stimulation with pneumococcus lung-resident CD4+ cells produced multiple protective cytokines including IL-17A, IFN-γ, IL-22, IL-2, and TNF-α. In protected lungs, there were increased numbers of CD4+ resident memory T (TRM) cells, confined to the anatomic region of the initial infections. Heterotypic protection was also confined to the site of previous pneumococcal infections. Previously-exposed mice challenged in their contralateral lobes were not protected. RNAseq analysis of heterotypic lungs 24h after Sp3 infection revealed an enrichment of lymphocyte-related pathways including immunoglobulin and other B cell-related genes. B cell-deficient µMT-/- mice exposed to pneumococci had intermediate protection against Sp3 pneumonia, better than naïve mice but less effective than fully immunocompetent peers. Plasma from mice previously exposed to pneumococci was sufficient to protect naïve mice against Sp3 pneumonia. We conclude that mechanisms of naturally-acquired heterotypic protection against pneumococcus involve both lung-resident cell-mediated and humoral immunity and importantly this protection can be compartmentalized within the lung. Advancing our understanding of these mechanisms will guide future vaccine development and treatment strategies for lung disease.

This thesis deals with problems of vaccination, which is today a very discussed topic. Thesis is focused on general information about immunization, vaccine calendar, safety and legislation on vaccination. In the thesis is also examined public opinion about vaccination. The thesis is mainly focused on optional vaccination against pneumococcal infections. Specifically looks at the factors which influence consumer decision-making in the selection of pneumococcal vaccines. Compared are the two competing preparations, Synflorix and Prevenar. The objective of the thesis is to identify and compare factors influencing the consumer choice of vaccine against pneumococcal infections.

As infecções por Streptococcus pneumoniae (pneumococo) ainda desafiam os sistemas de saúde em todo mundo. Este é um estudo observacional, de seguimento retrospectivo, que avaliou aspectos microbiológicos e clínicos das cepas de pneumococo isoladas de pacientes com doença invasiva pneumocócica (DIP) isolados nos Departamentos Regionais de Saúde (DRS) de Araraquara, Barretos, Franca e Ribeirão Preto, em um período de 16 anos (1998-2013). As informações foram obtidas junto ao Instituto Adolfo Lutz e, no banco de dados do Hospital das Clínicas de Ribeirão Preto (HCRP). Analisou-se 796 linhagens, com predominio do gênero masculino (58,9%), da faixa etária de 20 a menores de 60 anos de idade (32,2%) e do período de 2003 a 2010 (60,2%). As DIPs mais comuns foram a meningite (45,7%) e a pneumonia (45,0%). Quanto aos sorotipos mais frequentes, observou-se em 83,3%: 14, 3, 19F, 1, 6A, 6B, 23F, 9V, 18C, 19A, 12F, 4, 7F, 5, 22F, 11A, 8, 9N, 10A e 15C, sendo o 14 o mais comum nos quatro DRS estudados. Os sorotipos 14, 3 e 19F foram mais frequentes na meningite, enquanto os sorotipos 14, 3 e 1 na pneumonia. Após 2010, verificou-se diminuição dos sorotipos 14, 1, 23F e 5 e aumento de 12F, 11A e 8, não contidos na vacina. A resistência à penicilina foi de 14,8%, sendo 3,0% resistência intermediária e 11,8% de resistência plena. Para ceftriaxona, 5,3% foram não sensíveis. A sensibilidade ao cloranfenicol, eritromicina e ceftriaxona manteve-se acima dos 90%, no período estudado. O maior nível de resistência foi observado para Sulfametoxazol/trimetoprim (49,4%). Destaca-se o aumento dos sorotipos 12F, 11A e 8 após a vacinação, considerando que nenhum deles compõe as vacinas conjugadas disponíveis. Observou-se variabilidade de resistência entre os diferentes sorotipos de pneumococo. A DIP mais frequente nos pacientes cadastrados no HCRP foi a pneumonia (67,8%), seguida da meningite (22,9%) tendo como sorotipos mais frequentes 14, 6A, 23F, 1, 3, 18C, 19F, 12F, 4,9V, 6B e 19A. Destes pacientes 67,5% apresentaram cura sem sequelas, 6,9% tiveram algum tipo de sequela e 25,6% evoluíram para óbito. A pneumonia causou 18,2% dos óbitos, principalmente na faixa etária de 20 a menores de 60 anos de idade. Os sorotipos 12F, 14, 18C, 9V, 18A, 19A e 23F foram responsáveis por 64,9% dos óbitos por meningite, enquanto os sorotipos 3, 14, 9V, 6B, 23F e 19F estiveram envolvidos em 63,4% das mortes por pneumonia. Entre os pacientes que morreram 68,2% tinham algum tipo de comorbidade, sendo HIV/AIDS, alcoolismo e câncer as mais comuns. A faixa etária com 60 anos ou mais foi a mais significativa (OR=4,2) para o insucesso, independente da presença de comorbidade. A presença do sorotipo 18C foi fator de risco significativo tanto na análise bruta (OR=3,8), quanto ao ajustar por comorbidade (OR=5,0) ou ajustada por idade (OR=5,4). O mesmo ocorreu para o sorotipo 12F (respectivamente, OR=5,1, OR=5,0 e OR=4,7). Observou-se alterações na circulação de alguns sorotipos de pneumococo no período pós VPC10. Ressalta-se a importância da continuidade da vigilância das DIPs, afim de determinar oscilações clínicas e microbiológicas da doença. Além disto, na era das vacinas conjugadas, o contínuo monitoramento sobre a distribuição de sorotipos na população é necessário para a avaliação do impacto e adequação da imunização / Infections by Streptococcus pneumoniae (pneumococcus) are still a challenge to health systems worldwide. An observational retrospective study was developed to assess microbiological and clinical aspects of pneumococcus strains isolated from patients with invasive pneumococcal diseases (IPD) which were isolated in the Regional Health Departments (DRS) of Araraquara, Barretos, Franca and Ribeirão Preto, in a period of 16 years (1998-2013). Data were obtained at the Adolfo Lutz Institute and in databases of the Clinics Hospital of Ribeirão Preto (HCRP). A total of 796 strains were analyzed, with prevalence of male individuals (58.9%), aged between 20 and 60 years (32.2%), and in the period between 2003 and 2010 (60.2%). The most common IPD were meningitis (45.7%) and pneumonia (45.0%). Regarding the most frequent serotypes, in 83.3% they were: 14, 3, 19F, 1, 6A, 6B, 23F, 9V, 18C, 19A, 12F, 4, 7F, 5, 22F, 11A, 8, 9N, 10A and 15C, with 14 being the most common in the four DRS studied. Serotypes 14, 3 and 19F were more frequent in meningitis, whereas serotypes 14, 3 and 1 were more frequent in pneumonia. After 2010, there was a decrease in serotypes 14, 1, 23F and 5, and an increase in 12F, 11A and 8, which are not included in the vaccine. Resistance to penicillin was 14.8%, with 3.0% being intermediate, and 11.8% full resistance. For ceftriaxone, 5.3% were not sensitive. Sensitivity to chloramphenicol, erythromycin and ceftriaxone remained over 90% in the studied period. The highest level of resistance was observed for Sulfamethoxazole/trimethoprim (49.4%). It is noteworthy that there was an increase in the s serotypes 12F, 11A and 8 after vaccination, considering that none of them make up the combined vaccines available. Resistance varied among the different serotypes of pneumococcus. The most frequent IPD in the patients registered in the HCRP was pneumonia (67.8%), followed by meningitis (22.9%), with the most frequent serotypes being 14, 6A, 23F, 1, 3, 18C, 19F, 12F, 4, 9V, 6B and 19A. Of these patients, 67.5% were cured without sequela, 6.9% had some sort of sequela and 25.6% evolved to death. Pneumonia caused 18.2% of the deaths, mainly in the age range between 20 and 60 years. Serotypes 12F, 14, 18C, 9V, 18A, 19A and 23F were responsible for 64.9% of the deaths by meningitis, whereas serotypes 3, 14, 9V, 6B, 23F and 19F were involved in 63.4% of the deaths by pneumonia. Among the patients who died, 68.2% had some sort of comorbidity, with HIV/AIDS, alcoholism and cancer being the most common. The age range over 60 years was the most significant (OR=4.2) for failure, regardless of the presence of a comorbidity. The presence of serotype 18C was a significant risk factor both in the gross analysis (OR=3.8), and in the adjustment as for comorbidity (OR=5.0) or age (OR=5.4). This was also true for the serotype 12F (respectively, OR=5.1, OR=5.0 and OR=4.7). There were alterations in the circulation of some pneumococcus serotypes in the period after VPC10. it is emphasized the importance of continued monitoring of DIPs, in order to determine clinical and microbiological fluctuations of the disease. In addition, in the era of combined vaccines, it is necessary to keep monitoring the distribution of serotypes in the population to assess the impact and adequacy of immunization

Streptococcus pneumoniae é responsável por milhões de mortes anuais no mundo todo. As vacinas atuais são baseadas em polissacarídeos capsulares e apresentam cobertura limitada. Assim, diversas proteínas tem sido estudadas como alternativas vacinais, dentre as quais se destacam PspA e PLY. Os objetivos deste estudo foram caracterizar produção de anticorpos e a resposta celular induzida pela imunização com vacinas híbridas PspA-PLY em modelo de pneumonia. Os anticorpos apresentaram elevada capacidade de ligação a pneumococos expressando PspAs de família 2, bem como um aumento na deposição de complemento nestes isolados. A imunização com as proteínas híbridas protegeu os camundongos do desafio sistêmico com pneumococo contendo PspA de família 2. Foi desenvolvido um modelo de pneumonia lobar em camundongos, onde a imunização com PspA-PLY induziu um aumento de IL-6 e TNF nos pulmões após o desafio, levando a uma redução no número de bactérias nos pulmões dos animais. Os dados sugerem que a fusão de PspA à PLY é capaz de ampliar a cobertura protetora a isolados expressando PspAs distintas, e que essa mesma vacina á capaz de proteger os animais contra pneumonia, pela indução precoce de citocinas como IL-6 e TNF-a nos pulmões. / Streptococcus pneumoniae is responsible for millions of deaths annually around the globe. The current vaccines are based on capsular polysaccharides, and have limited coverage. Thus, several proteins have been investigated as alternative vaccines, including PspA and PLY. The present study aimed at characterizing the antibody production and cellular immune response induced by mouse immunization with PspA-PLY hybrid vaccines in a pneumonia model. The induced antibodies demonstrated a strong recognition of pneumococci expressing family 2 PspA molecules, as well as an enhancement in complement deposition in their surface. Immunization with the fusion protein protected mice from systemic challenge with a pneumococcal isolate bearing a family 2 PspA. A model of lobar pneumonia was developed in BALB/c mice, where the immunization with the PspA-PLY fusion induced an increase in IL-6 and TNF-a production in the lungs after pneumococcal challenge, leading to a reduction on bacteria load in the lungs of immunized mice. The data suggests that fusion of PspA to PLY is capable of increasing vaccine coverage aginst pneumococcal infection with isolates bearing family 2 PspAs, and confer protection in mice against pneumonia, by the early production of IL-6 and TNF-a in the lungs.

As infecções por Streptococcus pneumoniae (pneumococo) ainda desafiam os sistemas de saúde em todo mundo. Este é um estudo observacional, de seguimento retrospectivo, que avaliou aspectos microbiológicos e clínicos das cepas de pneumococo isoladas de pacientes com doença invasiva pneumocócica (DIP) isolados nos Departamentos Regionais de Saúde (DRS) de Araraquara, Barretos, Franca e Ribeirão Preto, em um período de 16 anos (1998-2013). As informações foram obtidas junto ao Instituto Adolfo Lutz e, no banco de dados do Hospital das Clínicas de Ribeirão Preto (HCRP). Analisou-se 796 linhagens, com predominio do gênero masculino (58,9%), da faixa etária de 20 a menores de 60 anos de idade (32,2%) e do período de 2003 a 2010 (60,2%). As DIPs mais comuns foram a meningite (45,7%) e a pneumonia (45,0%). Quanto aos sorotipos mais frequentes, observou-se em 83,3%: 14, 3, 19F, 1, 6A, 6B, 23F, 9V, 18C, 19A, 12F, 4, 7F, 5, 22F, 11A, 8, 9N, 10A e 15C, sendo o 14 o mais comum nos quatro DRS estudados. Os sorotipos 14, 3 e 19F foram mais frequentes na meningite, enquanto os sorotipos 14, 3 e 1 na pneumonia. Após 2010, verificou-se diminuição dos sorotipos 14, 1, 23F e 5 e aumento de 12F, 11A e 8, não contidos na vacina. A resistência à penicilina foi de 14,8%, sendo 3,0% resistência intermediária e 11,8% de resistência plena. Para ceftriaxona, 5,3% foram não sensíveis. A sensibilidade ao cloranfenicol, eritromicina e ceftriaxona manteve-se acima dos 90%, no período estudado. O maior nível de resistência foi observado para Sulfametoxazol/trimetoprim (49,4%). Destaca-se o aumento dos sorotipos 12F, 11A e 8 após a vacinação, considerando que nenhum deles compõe as vacinas conjugadas disponíveis. Observou-se variabilidade de resistência entre os diferentes sorotipos de pneumococo. A DIP mais frequente nos pacientes cadastrados no HCRP foi a pneumonia (67,8%), seguida da meningite (22,9%) tendo como sorotipos mais frequentes 14, 6A, 23F, 1, 3, 18C, 19F, 12F, 4,9V, 6B e 19A. Destes pacientes 67,5% apresentaram cura sem sequelas, 6,9% tiveram algum tipo de sequela e 25,6% evoluíram para óbito. A pneumonia causou 18,2% dos óbitos, principalmente na faixa etária de 20 a menores de 60 anos de idade. Os sorotipos 12F, 14, 18C, 9V, 18A, 19A e 23F foram responsáveis por 64,9% dos óbitos por meningite, enquanto os sorotipos 3, 14, 9V, 6B, 23F e 19F estiveram envolvidos em 63,4% das mortes por pneumonia. Entre os pacientes que morreram 68,2% tinham algum tipo de comorbidade, sendo HIV/AIDS, alcoolismo e câncer as mais comuns. A faixa etária com 60 anos ou mais foi a mais significativa (OR=4,2) para o insucesso, independente da presença de comorbidade. A presença do sorotipo 18C foi fator de risco significativo tanto na análise bruta (OR=3,8), quanto ao ajustar por comorbidade (OR=5,0) ou ajustada por idade (OR=5,4). O mesmo ocorreu para o sorotipo 12F (respectivamente, OR=5,1, OR=5,0 e OR=4,7). Observou-se alterações na circulação de alguns sorotipos de pneumococo no período pós VPC10. Ressalta-se a importância da continuidade da vigilância das DIPs, afim de determinar oscilações clínicas e microbiológicas da doença. Além disto, na era das vacinas conjugadas, o contínuo monitoramento sobre a distribuição de sorotipos na população é necessário para a avaliação do impacto e adequação da imunização / Infections by Streptococcus pneumoniae (pneumococcus) are still a challenge to health systems worldwide. An observational retrospective study was developed to assess microbiological and clinical aspects of pneumococcus strains isolated from patients with invasive pneumococcal diseases (IPD) which were isolated in the Regional Health Departments (DRS) of Araraquara, Barretos, Franca and Ribeirão Preto, in a period of 16 years (1998-2013). Data were obtained at the Adolfo Lutz Institute and in databases of the Clinics Hospital of Ribeirão Preto (HCRP). A total of 796 strains were analyzed, with prevalence of male individuals (58.9%), aged between 20 and 60 years (32.2%), and in the period between 2003 and 2010 (60.2%). The most common IPD were meningitis (45.7%) and pneumonia (45.0%). Regarding the most frequent serotypes, in 83.3% they were: 14, 3, 19F, 1, 6A, 6B, 23F, 9V, 18C, 19A, 12F, 4, 7F, 5, 22F, 11A, 8, 9N, 10A and 15C, with 14 being the most common in the four DRS studied. Serotypes 14, 3 and 19F were more frequent in meningitis, whereas serotypes 14, 3 and 1 were more frequent in pneumonia. After 2010, there was a decrease in serotypes 14, 1, 23F and 5, and an increase in 12F, 11A and 8, which are not included in the vaccine. Resistance to penicillin was 14.8%, with 3.0% being intermediate, and 11.8% full resistance. For ceftriaxone, 5.3% were not sensitive. Sensitivity to chloramphenicol, erythromycin and ceftriaxone remained over 90% in the studied period. The highest level of resistance was observed for Sulfamethoxazole/trimethoprim (49.4%). It is noteworthy that there was an increase in the s serotypes 12F, 11A and 8 after vaccination, considering that none of them make up the combined vaccines available. Resistance varied among the different serotypes of pneumococcus. The most frequent IPD in the patients registered in the HCRP was pneumonia (67.8%), followed by meningitis (22.9%), with the most frequent serotypes being 14, 6A, 23F, 1, 3, 18C, 19F, 12F, 4, 9V, 6B and 19A. Of these patients, 67.5% were cured without sequela, 6.9% had some sort of sequela and 25.6% evolved to death. Pneumonia caused 18.2% of the deaths, mainly in the age range between 20 and 60 years. Serotypes 12F, 14, 18C, 9V, 18A, 19A and 23F were responsible for 64.9% of the deaths by meningitis, whereas serotypes 3, 14, 9V, 6B, 23F and 19F were involved in 63.4% of the deaths by pneumonia. Among the patients who died, 68.2% had some sort of comorbidity, with HIV/AIDS, alcoholism and cancer being the most common. The age range over 60 years was the most significant (OR=4.2) for failure, regardless of the presence of a comorbidity. The presence of serotype 18C was a significant risk factor both in the gross analysis (OR=3.8), and in the adjustment as for comorbidity (OR=5.0) or age (OR=5.4). This was also true for the serotype 12F (respectively, OR=5.1, OR=5.0 and OR=4.7). There were alterations in the circulation of some pneumococcus serotypes in the period after VPC10. it is emphasized the importance of continued monitoring of DIPs, in order to determine clinical and microbiological fluctuations of the disease. In addition, in the era of combined vaccines, it is necessary to keep monitoring the distribution of serotypes in the population to assess the impact and adequacy of immunization

Streptococcus pneumoniae é responsável por milhões de mortes anuais no mundo todo. As vacinas atuais são baseadas em polissacarídeos capsulares e apresentam cobertura limitada. Assim, diversas proteínas tem sido estudadas como alternativas vacinais, dentre as quais se destacam PspA e PLY. Os objetivos deste estudo foram caracterizar produção de anticorpos e a resposta celular induzida pela imunização com vacinas híbridas PspA-PLY em modelo de pneumonia. Os anticorpos apresentaram elevada capacidade de ligação a pneumococos expressando PspAs de família 2, bem como um aumento na deposição de complemento nestes isolados. A imunização com as proteínas híbridas protegeu os camundongos do desafio sistêmico com pneumococo contendo PspA de família 2. Foi desenvolvido um modelo de pneumonia lobar em camundongos, onde a imunização com PspA-PLY induziu um aumento de IL-6 e TNF nos pulmões após o desafio, levando a uma redução no número de bactérias nos pulmões dos animais. Os dados sugerem que a fusão de PspA à PLY é capaz de ampliar a cobertura protetora a isolados expressando PspAs distintas, e que essa mesma vacina á capaz de proteger os animais contra pneumonia, pela indução precoce de citocinas como IL-6 e TNF-a nos pulmões. / Streptococcus pneumoniae is responsible for millions of deaths annually around the globe. The current vaccines are based on capsular polysaccharides, and have limited coverage. Thus, several proteins have been investigated as alternative vaccines, including PspA and PLY. The present study aimed at characterizing the antibody production and cellular immune response induced by mouse immunization with PspA-PLY hybrid vaccines in a pneumonia model. The induced antibodies demonstrated a strong recognition of pneumococci expressing family 2 PspA molecules, as well as an enhancement in complement deposition in their surface. Immunization with the fusion protein protected mice from systemic challenge with a pneumococcal isolate bearing a family 2 PspA. A model of lobar pneumonia was developed in BALB/c mice, where the immunization with the PspA-PLY fusion induced an increase in IL-6 and TNF-a production in the lungs after pneumococcal challenge, leading to a reduction on bacteria load in the lungs of immunized mice. The data suggests that fusion of PspA to PLY is capable of increasing vaccine coverage aginst pneumococcal infection with isolates bearing family 2 PspAs, and confer protection in mice against pneumonia, by the early production of IL-6 and TNF-a in the lungs.